<template>
    <div class="list" ref="wrapper">
        <div>
            <div class="area">
                <div class="title border-topbottom">当前城市</div>
                <div class="button-list">
                    <div class="button-wrapper">
                        <div class="button">{{this.currentCity}}</div>
                    </div>
                </div>
            </div>
            <div class="area">
                <div class="title border-topbottom">热门城市</div>
                <div class="button-list">
                    <div class="button-wrapper" v-for="item of hot" :key="item.id" 
                    @click="handleCityClick(item.name)">
                        <div class="button">{{item.name}}</div>
                    </div>
                </div>
            </div>
            <div class="area" v-for="(item, key) of cities" :key="key" :ref="key">
                <div class="title border-topbottom">{{ key }}</div>
                <div class="item-list">
                    <div class="item border-bottom" v-for="innerItem of item" :key="innerItem.id" 
                    @click="handleCityClick(innerItem.name)">
                        {{ innerItem.name }}
                    </div>
                </div>
            </div>
        </div>
    </div>
</template>
  
<script>
import Bscroll from 'better-scroll'
// 使用 vuex 简化代码，mapState 的意思是把 vuex 里的数据映射到以下city 
// 这个组件的计算属性里，把 city 这个公用数据映射到 叫 city 的这个计算属性之中
import { mapState, mapMutations } from 'vuex'
export default {
    name: 'CityList',
    props: {
        hot: Array,
        cities: Object,
        letter: String
    },
    computed: {
      ...mapState({
        currentCity: 'city'
      })
    },
    methods: {
        handleCityClick (city) {
            this.changeCity(city)
            this.$router.push('/')
      },
      ...mapMutations(['changeCity'])
    },
    watch: {
        letter() {
            if (this.letter) {
                const element = this.$refs[this.letter][0]
                this.scroll.scrollToElement(element)
            }
        }
    },
    mounted() {
        this.scroll = new Bscroll(this.$refs.wrapper,{
            click: true
        })
    }
}
</script>
  
<style lang="less" scoped>
@import '~@/assets/styles/varibles.less';

.border-topbottom &:before {
    border-color: #ccc;
}

&:after {
    border-color: #ccc;
}

.border-bottom &:before {
    border-color: #ccc;
}

.list {
    overflow: hidden;
    position: absolute;
    top: 1.58rem;
    left: 0;
    right: 0;
    bottom: 0;
}

.title {
    line-height: .54rem;
    background: #eee;
    padding-left: .2rem;
    color: #666;
    font-size: .26rem;
}

.button-list {
    overflow: hidden;
    padding: .1rem .6rem .1rem .1rem;
}

.button-wrapper {
    float: left;
    width: 33.33%;
}

.button {
    margin: .1rem;
    padding: .1rem 0;
    text-align: center;
    border: .02rem solid #ccc;
    border-radius: .06rem;
}

.item-list {
    .item {
        line-height: .76rem;
        padding-left: .2rem;
    }
}
</style>
  